1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * HID support for Vivaldi Keyboard
4 *
5 * Copyright 2020 Google LLC.
6 * Author: Sean O'Brien <seobrien@chromium.org>
7 */
8
9 #include <linux/hid.h>
10 #include <linux/module.h>
11
12 #define MIN_FN_ROW_KEY 1
13 #define MAX_FN_ROW_KEY 24
14 #define HID_VD_FN_ROW_PHYSMAP 0x00000001
15 #define HID_USAGE_FN_ROW_PHYSMAP (HID_UP_GOOGLEVENDOR | HID_VD_FN_ROW_PHYSMAP)
16
17 static struct hid_driver hid_vivaldi;
18
19 struct vivaldi_data {
20 u32 function_row_physmap[MAX_FN_ROW_KEY - MIN_FN_ROW_KEY + 1];
21 int max_function_row_key;
22 };
23
function_row_physmap_show(struct device * dev,struct device_attribute * attr,char * buf)24 static ssize_t function_row_physmap_show(struct device *dev,
25 struct device_attribute *attr,
26 char *buf)
27 {
28 struct hid_device *hdev = to_hid_device(dev);
29 struct vivaldi_data *drvdata = hid_get_drvdata(hdev);
30 ssize_t size = 0;
31 int i;
32
33 if (!drvdata->max_function_row_key)
34 return 0;
35
36 for (i = 0; i < drvdata->max_function_row_key; i++)
37 size += sprintf(buf + size, "%02X ",
38 drvdata->function_row_physmap[i]);
39 size += sprintf(buf + size, "\n");
40 return size;
41 }
42
43 DEVICE_ATTR_RO(function_row_physmap);
44 static struct attribute *sysfs_attrs[] = {
45 &dev_attr_function_row_physmap.attr,
46 NULL
47 };
48
49 static const struct attribute_group input_attribute_group = {
50 .attrs = sysfs_attrs
51 };
52
vivaldi_probe(struct hid_device * hdev,const struct hid_device_id * id)53 static int vivaldi_probe(struct hid_device *hdev,
54 const struct hid_device_id *id)
55 {
56 struct vivaldi_data *drvdata;
57 int ret;
58
59 drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
60 hid_set_drvdata(hdev, drvdata);
61
62 ret = hid_parse(hdev);
63 if (ret)
64 return ret;
65
66 return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
67 }
68
vivaldi_feature_mapping(struct hid_device * hdev,struct hid_field * field,struct hid_usage * usage)69 static void vivaldi_feature_mapping(struct hid_device *hdev,
70 struct hid_field *field,
71 struct hid_usage *usage)
72 {
73 struct vivaldi_data *drvdata = hid_get_drvdata(hdev);
74 int fn_key;
75 int ret;
76 u32 report_len;
77 u8 *buf;
78
79 if (field->logical != HID_USAGE_FN_ROW_PHYSMAP ||
80 (usage->hid & HID_USAGE_PAGE) != HID_UP_ORDINAL)
81 return;
82
83 fn_key = (usage->hid & HID_USAGE);
84 if (fn_key < MIN_FN_ROW_KEY || fn_key > MAX_FN_ROW_KEY)
85 return;
86 if (fn_key > drvdata->max_function_row_key)
87 drvdata->max_function_row_key = fn_key;
88
89 buf = hid_alloc_report_buf(field->report, GFP_KERNEL);
90 if (!buf)
91 return;
92
93 report_len = hid_report_len(field->report);
94 ret = hid_hw_raw_request(hdev, field->report->id, buf,
95 report_len, HID_FEATURE_REPORT,
96 HID_REQ_GET_REPORT);
97 if (ret < 0) {
98 dev_warn(&hdev->dev, "failed to fetch feature %d\n",
99 field->report->id);
100 goto out;
101 }
102
103 ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
104 report_len, 0);
105 if (ret) {
106 dev_warn(&hdev->dev, "failed to report feature %d\n",
107 field->report->id);
108 goto out;
109 }
110
111 drvdata->function_row_physmap[fn_key - MIN_FN_ROW_KEY] =
112 field->value[usage->usage_index];
113
114 out:
115 kfree(buf);
116 }
117
vivaldi_input_configured(struct hid_device * hdev,struct hid_input * hidinput)118 static int vivaldi_input_configured(struct hid_device *hdev,
119 struct hid_input *hidinput)
120 {
121 return sysfs_create_group(&hdev->dev.kobj, &input_attribute_group);
122 }
123
124 static const struct hid_device_id vivaldi_table[] = {
125 { HID_DEVICE(HID_BUS_ANY, HID_GROUP_VIVALDI, HID_ANY_ID,
126 HID_ANY_ID) },
127 { }
128 };
129
130 MODULE_DEVICE_TABLE(hid, vivaldi_table);
131
132 static struct hid_driver hid_vivaldi = {
133 .name = "hid-vivaldi",
134 .id_table = vivaldi_table,
135 .probe = vivaldi_probe,
136 .feature_mapping = vivaldi_feature_mapping,
137 .input_configured = vivaldi_input_configured,
138 };
139
140 module_hid_driver(hid_vivaldi);
141
142 MODULE_AUTHOR("Sean O'Brien");
143 MODULE_DESCRIPTION("HID vivaldi driver");
144 MODULE_LICENSE("GPL");
145